


Insanity

by Anonymous



Series: You fucked me up. [1]
Category: Haikyuu!!
Genre: Ambiguous/Open Ending, Anal Sex, Barebacking, Bottom Kageyama Tobio, Cheating, Guilty Pleasures, Loneliness, M/M, Manipulation, Masturbation, Seduction, Top Oikawa Tooru, Voyeurism
Language: English
Status: Completed
Published: 2020-06-07
Updated: 2020-06-07
Packaged: 2021-03-03 18:48:21
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,877
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24580303
Author URL: https://archiveofourown.org/
Summary: Shameless. Disgusting. Such a tease.He couldn’t help himself.
Relationships: Iwaizumi Hajime/Oikawa Tooru, Kageyama Tobio/Oikawa Tooru
Series: You fucked me up. [1]
Series URL: https://archiveofourown.org/series/1992385
Comments: 18
Kudos: 324
Collections: Anonymous





	Insanity

**Author's Note:**

> WARNING!
> 
> This is a smut and adultery fiction. Oikawa is cheating on Iwaizumi with Kageyama. I don't support cheating and manipulation irl, this is just my fantasy. Please read at your own risk!

Tokyo was very different from Miyagi. Back home, Sendai city was very peaceful and everything went a bit slow at least for him. On the other hand, everything in Tokyo was very fast and lively. Oikawa was partially overwhelmed at first as he was alone in a new city. But, almost two years had passed and his life was running _smoothly_. Although, he and Iwaizumi went to different universities, they managed to maintain their relationship by visiting each other.

  
It was a new semester in Tokyo University. He was excited to meet the new members of volleyball club. He couldn’t wait to see new faces and maybe meet some of his old teammates. He remembered his conversation with some of his juniors from Aoba Johsai about studying in Tokyo months ago. So, there is a good chance they will be teammates once more.

  
He reminisced as he walked to the gym for morning practice. There was a lot of people inside the gym and some faces that he didn’t recognized; possibly the new recruits. He strolled to the locker room to put his bags before coming back to the gym. Once he came back, the coach was ordering the players to gather. He said some boring stuffs like their goals this year and what he expects from the new members.

  
The coach left the rest to the captain to start their usual routine. The captain asked them to introduce their names and positions starting from the seniors. When it was the new members’ turn he swept his gaze to some new faces one by one; trying to remember them. He went rigid as his eyes caught someone familiar.

  
Tobio. He looked different from the last time he saw him at Sendai City Gymnasium. His hair is still silky but slightly longer and arched a bit at the end. The soft curve of his jaws looked more prominent now as his body became sturdy and broad. And that pair of blue eyes; there is an underlying confidence as you looked at them carefully. Tobio looked different but it’s not something surprising. 

  
As if reading his mind, Tobio stared back at him. He quickly averted his gaze somewhere else; trying to act as normal as possible.

  
Well, not that it matters. As long as Tobio didn’t approach him like in junior high, he will be fine.

* * *

  
He just walked out of his class when the phone on his hand lighted with a notification, enough for him to catch the application name. He unlocked his phone and read the message.

  
**[Iwa-chan]: Hey, how’s your new semester?**  
**[Iwa-chan]: I met Kunimi and Kindaichi here. We’re going to have lunch together!**

  
He smiled at the messages but once again being reminded about his annoying junior with the mention of Kunimi and Kindaichi. He wanted to rant to Iwaizumi about what happened but didn’t want the other male to worry and scold him endlessly, especially regarding that _event_ in junior high.

  
**[Me]: It’s fine, nothing special**  
**[Me]: Iwa-channn! Why are you so lucky? There is none of Aoba Johsai members here**  
**[Me]: I’m so lonely!（ｉДｉ）**

  
He sent the replies before heading to get lunch. Well, it’s not like he’s lying to Iwaizumi.

* * *

  
He ate his lunch at a nearby local restaurant alone. Occasionally, his friends or the girls will ask him to join them but today he felt like eating alone. He remembered when he first arrived to Tokyo he felt weird and couldn’t get used to the momentum, but now it’s more like a boring routine.

  
_The more you grow up the more you realize you’re on your own._

  
He wished Iwaizumi was here with him. They could only meet once a month, sometimes none. They face timed each other but it’s getting dull. There’s not much to tell about their lives anymore. The conversations are full with studies and assignments that they couldn’t understand; considering their different major. He knew they’re starting to drift apart.

  
_It would be easier if they’re in the same university._

  
He shook his head lightly. No, he can’t be selfish because he needed a company. Iwaizumi has his own dreams and life. He needed to respect that.

  
He sighed to release some air before finishing his meal.

* * *

  
A week had passed since the opening of the new semester. Throughout the week, Tobio had never tried to interact with him. But either way, he couldn’t help but to feel cautious around the other male.

  
Today, the team was practicing their defence and offense. Some of the players will serve and the rest will try to receive the ball at the other side of the court. Once the players meet a certain number of serves, they will exchange with the receiver.

  
By the time they were finished, many volleyballs were rolling around the gym. The coach was reminding them to clean up the mess before he headed out to fill the daily journal. He quickly picked up the ones near him, hoping to get home faster. He was putting them in the nearest cart when a movement caught his eyes.

  
Tobio with his tight shorts; bending over to pick up the volleyballs. The thin fabric stretched and hugged his curves perfectly as the younger male lean down to pick several at once. Of course, Tobio looked so oblivious as he stood up and walked to one of the cart at the side of the court.

  
He gulped unconsciously at the sight before squinting his eyes in annoyance. He walked towards the bench to swallow down tons of water from his bottle; hoping to clear his mind. He definitely needed some sleep after this.

* * *

  
It’s a common information that the captain and the vice-captain are the only one who held the key to the gymnasium besides the supervisor. Therefore, the captain will unlock the gym for morning practice and the vice-captain will lock it at the end of the day. Many players took additional practice after courses and Oikawa joined them as he will be the last one to leave the gym.

  
The last chorus of greetings filled the gym as he tucked the net inside the storage room. The gym was empty as he was heading to the locker room; ready to change into his casual clothes. Tobio was there; rummaging aggressively inside the locker. The older male narrowed his eyes before choosing to ignore him; quickly switching his shirt with a new one and walked out of the locker room. He waited for Tobio to come out before locking the door; double checking it for good measure and walked away with hurried pace.

  
It’s not rare for him to find Tobio in the locker alone since that day. Always half-dressed, shirt was not fully buttoned, showing the fair skin underneath. The belt was loosely hanging low on his hips; exposing yet another surface of skin. He had never started a conversation or a mere small talk, but neither Tobio. So, he tried to mind his own business and change as fast as he could.

  
He found this routine a little odd. Instead of insistently asking him just like junior high, this Tobio is very quiet and constantly watching. And yet, with his calm demeanour, Tobio managed to make his existence stronger.

* * *

  
It was almost two weeks after the start of a new semester that the sport team agreed to make a welcoming party for the new members. The captain managed to convince some seniors to lend them the frat-house for the party. They called it a welcoming party but it’s just an excuse to drink alcohol.

  
He usually drinks enough before he was drunk. Maybe a little tipsy but he still could think clearly. He shared a few drinks with his teammates. It was his third cup and he wanted to go home. He took a few minutes to relax and clear his mind before going into the kitchen area to get some water.

  
He managed to gulp down a handful of liquid before walking towards the entrance. One of the doors in the hallway was slightly opened. He can’t help but to peek a little inside as he walked towards the main door.

  
There were two men inside. One was sitting on a single bed and the other was on the floor. The sounds they made were pretty loud from where he was standing but still inaudible from the crowd. The man on the bed was muttering and cursing at how good the other’s mouth as the black haired male bobbing his head without hesitation. He could see the man’s movement getting sloppy as he took the other in. Not long, the man on the bed went stiff and moaned loudly. But the other guy kept sucking and bobbing, making his partner whined in pleasure.

  
The man on the floor was turning around to glance at the door but he managed to stay out of the sight. He leaned to the wall as he recognized one of them.

  
He went back to the main room where the party was still pretty much alive. He managed to surpass the cheers and laughter of his teammates as they were dancing and fooling around. He walked with long stride before locking the bathroom door. He turned down the toilet seat so he could settle on it.

  
“Fuck,” He cursed as he closed his eyes with his head hitting the tile on the back of the facilities.

  
He stared at the lamp that was hanging on the ceiling before glancing at the bulge in front of him. He glared at it; hoping for the heat to calm down. But every time he tried to rationalize his mind, he kept imagining _Tobio on his knees, licking his lips-_

  
“Fuck it.” He cursed once again and undid his pants.

  
There’s a noticeable stain on the fabric. He pulled the boxer down, freeing his cock. He stared at the heat hesitantly before giving it a stroke.

  
He moaned while imagining Tobio with his tight shorts; bending over and making the fabric stretched perfectly around his ass. That soft skin underneath his shirt begging to be touched and marked. He imagined the sight from before, Tobio taking the stranger’s cock to the hilt. And gosh, how he could taste the pleasure as that stranger’s moaned while Tobio was taking him. How Tobio kept sucking like a good boy he is even after the climax; cleaning that dirty cock until the last drop.

  
He came for the second time, imagining Tobio instead his boyfriend.

  
_I’m really going to hell._

* * *

  
He avoided Tobio after that party. No one noticed since they’ve never interacted with each other before. Tobio also stopped spending extra time in the locker room. He should be grateful that things would go back to normal. It’s for the better after all.

  
He was changing his clothes longer than usual. He was about to put on his shirt when he heard his phone buzzed on the bench. He grabbed the phone and was going to check when the door of the locker room was opened.

  
“Ah, sorry. I think I drop my commuter card,” Tobio said nonchalantly while walking passed him; knowing that the older male will not reply him.

  
Tobio put his bag on the bench across from him and started looking. He looked away and ignored the other’s presence as he went to check his phone again. He sat on the bench and unlocked his phone before opening the app. Right when he was waiting for the message to come out, he heard a loud sound from the opposite bench behind him.

  
He jumped at the intrusion before turning around to complain at Tobio for the ruckus. And he was there; bent over on the floor with his lower part high, facing him. The other male was searching under the locker; his back arching in a nice curve. Little by little nearing his crotch before pulling away again.

  
_Shameless. Disgusting. Such a tease._

He couldn’t help himself.

“Did you... find it?”

  
There was a silence before Tobio straighten his back; slowly facing him. Tobio looked at him up and down before replying.

  
“Why don’t you help me, Oikawa-san?” He said softly but with such confidence, as if he knows everything that’s going to happen.

  
He didn’t stop his body when he tossed the phone and swiftly pulled Tobio by the waist onto his lap and kissed him roughly; both fighting for dominance. Tobio turned around with the help of his hands on the younger’s waist and quickly wrapped his hands around his neck, pulling him deeper into the kiss; tasting each other. They both pulled away, brown eyes wavering and blue eyes deciding. Tobio gave him a knowing look before grinding his ass against the bulge, making him growled.

  
“Shamelessly teasing me, to get me to fuck you? You’ll love that, Tobio?” He said, both hands on the other’s ass, not stopping the sinful act.

  
“Ah, yes! Please Tooru,”

  
He laid and pushed Tobio softly onto the floor; still grinding each other. He teared Tobio’s shirt and undid his own pants. Tobio slowly took off his shorts and boxer down to his knees; putting a clear show for him.

  
“Tooru,” Tobio called him softly while spreading his knees apart; submitting himself.

  
He couldn’t help but gulped at the sight. There is a black butt plug. Tobio pulled the plug a little before pushing it inside; showing how easy it went in and out of his rim. When Tobio finally pulled out, he present his already prepared hole to Oikawa.

  
“Did you prepare for me, Tobio? You want me inside?” Oikawa asked while slowly slipping in two fingers in easily; curling around the heat.

  
Tobio nodded, clenching while moaning in pleasure; begging for him to calm the itch. He felt Tobio’s foot on his shoulder; slowly trailing down onto his torso and finally arrived on his crotch. He gave him a soft nudge before pushing at the growing bulge.

  
“God, Tobio. Fuck, turn around.” He whispered, pulling his fingers while giving Tobio a chaste kiss on the lips.

  
Tobio did as he was told; swiftly bending on his knees while stealing a glance at him. He was slowly closing in and licking at the soft skin before pushing his tongue inside. He heard Tobio moaned louder while pushing his hips for more. He continued to fuck Tobio as the latter kept begging incoherently. Finally, he pulled away and slapped the cheeks several times, leaving prominent red marks.

  
_He must have been crazy._

  
“Tooru, please. I want yours inside. Fill me,” Tobio begged between the moans while looking back at him with such a wrecked expression.

  
He couldn’t help but to undo his boxers; freeing his cock while Tobio on his knees, spreading his cheeks for the older man to enter. He bit into Tobio’s shoulder while stroking his cock, _stop me_ , before pushing inside in one go.

  
“Fuck. So tight and so wet, Tobio,” He cursed, grabbing Tobio’s hips while fucking into him continuously. Tobio also pushed back as he pushed in; hitting the prostate a few times.

  
“So perfect,” He whispered, hugging the other male from behind while thrusting franticly; rough and sloppy.

  
The walls were sucking and tightening around him as if asking him to stay forever. He kept pushing as his mind trying to process the situation. _This is wrong. This has to be a dream. A bad fever dream. He need to-Fuck_. He felt the other male clenched hard as he buried all the way inside. He couldn’t help as a little part of his mind thinking:

  
_No, this is heaven._

  
“I’m cumming. Fuck, I’m cumming.” He moaned while sucking at the younger’s neck; leaving a nasty mark on his skin.

  
“Inside. Please, Tooru.”

  
Tooru pushed one last time before coming inside; filling him with his hot fluids. He came a second later; untouched. He could feel Tooru’s weight slowly downing on him. Tooru was still squirting inside, filling him until he’s slightly swollen. He could feel his inside clenching several times from the climax; taking everything Tooru gave him.

  
He could feel a light buzz came from beside him. It’s Tooru’s phone. He sneaked a glance at the screen.

  
**[Iwa-chan]: Hey, it’s been 2 months since the last time we met. I’m thinking about visiting you next week. Call me when you get home**  
**[Iwa-chan]: I love you, Tooru :)**

  
Tooru already stopped coming and yet he didn’t pull out and just leaned on him. He could feel the other’s evening breath on his back.

  
“Tooru,” He called the brunette while tightening his inside.

  
He could feel Tooru’s head lifted off his back; looking at him with such a complicated expression. He turned around so he’s facing Tooru; the other’s cock slowly pulling out at the process. He warped his hands around Tooru’s neck while playing with his brown curls before connecting their lips once again with an innocent kiss. He could feel the other’s lips hesitantly returning the kiss.

  
“Tooru,” He called again sweetly, locking his legs around Tooru’s waist.

  
They stared at each other’s eyes and kissed again passionately. Tobio smiled then moaned the other’s name continually as he felt a hardening cock pushing inside him.

**Author's Note:**

> I started writing this fanfic two weeks ago. I thought I'm gonna leave this fanfic in my storage because I'm so embarrassed writing a smut fiction (this is my first smut). But hey, Oikage tag is lacking smut. So I decided to post this.
> 
> I have an idea for a sequel/prequel but I don't know if I can write a smut fiction again.
> 
> I'm sorry for the grammar or typo. English is not my first language and I don't have a beta (I usually have, but I'm ashamed to show her this story). I just read this two times to make sure, but I guess there must be some errors here and there. Anyway, thanks for reading!


End file.
